Michigan DNR
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A lake trout caught in Lake Superior was tested by the Michigan DNR and discovered to be the oldest specimen on record. The average lifespan of a laker is 25-30 years and this fish was over double that age.
To put this exceptional fish in context, this lake trout was so old it spanned 12 presidential elections and was alive during JFK’s time in office, according to MLive.
62-Year-Old Lake Trout Is Oldest Ever Caught
Michigan DNR
The fish was landed on Lake Superior two years ago, back in 2023, 40 miles north of Grand Marais near the Canadian border. It was captured by field biologists from the Michigan Department of Natural Resources Marquette Fisheries Research Station.
The 4.6-pound lake trout received a special name from the Michigan DNR biologists, ‘Mary Catherine.’ And by testing the otolith (‘ear stone’) on the fish, the most reliable way to measure a fish’s age, they determined it was born in 1961!
Michigan DNR
In the DNR’s press release, they said if this “fish went to school (high school that is, not just schools of fish), she would have graduated from Klondike Reef High School in the same year as Meg Ryan, Princess Diana and Barack Obama reached that milestone.”
Cold water fish live longer!
Lake trout are a northern species, we most certainly do not have them down my way in Florida. I have only ever caught them in upstate New York in the Adirondack Mountains but they are prevalent across the northern portion of the country and Canada, in deep lakes with cold water.
This species can grow to enormous sizes. The IGFA all-tackle fishing world record for lake trout is a 70-pound, 0 ounce fish caught on Great Bear Lake in Canada’s Northwest Territories back in August, 1995.
A 73-pound lake trout was caught in Colorado in 2023, the same year Mary Katherine the oldest lake trout in history was caught in Lake Superior, but the Colorado fish was released and thus is not an official fishing world record.
As a cold water species, the lake trout has a slower metabolism than warm water species. This ultimately contributes to a longer lifespan as it slows down overall metabolic rates, and metabolic decay and oxidization.
There are many contributing factors to why cold water species live longer, but that’s a main contributor. Others are fewer parasites in the frigid water, slower growth rates, and many other factors.
Why this fish was only 4.6 pounds but 62 years old is interesting though, and I’m not sure we have that answer yet. Genetics certainly plays a massive role in growth. It is possible that by studying this specimen the Michigan DNR biologists will be able to learn more about why it remained under 5 pounds while some lake trout balloon to over 70 pounds.
The Michigan state fishing record for lake trout is a 61.5 pound fish that measured 49 inches long. It was caught on Lake Superior way back in 1997 by an angler drift fishing with a jig. All of that is to say, there are some really big lakers in Lake Superior and in the state of Michigan, and Mary Katherine is a true anomaly in more ways than one.